Intensified pegylated-asparaginase in consolidation therapy improved outcome of allogeneic hematopoietic stem cell transplantation for adult T-cell acute lymphoblastic leukemia

Research on the optimal consolidation therapy for adult T-cell acute lymphoblastic leukemia (T-ALL) remains limited, and how to integrate pediatric-inspired chemotherapy with allogeneic hematopoietic stem cell transplantation (SCT) is less addressed. Based on retrospective analysis indicating that 4 doses of pegylated-asparaginase (PEG-Asp) prior to SCT were optimal for survival, we designed a PEG-Asp-intensified pediatric-inspired regimen, PDT-ALL-2016, for adult T-ALL (NCT03564704). In this protocol, SCT administered following 4 or 5 doses of PEG-Asp. The impact of PEG-Asp on transplantation outcomes was evaluated in two cohorts: the prospective PDT-ALL-2016 cohort (2016.1-2021.12, N = 63) and the retrospective adult regimen cohort (2008.1-2015.12, N = 61). With intensified PEG-Asp consolidation, the prospective cohort exhibited superior survival compared to the retrospective cohort. Furthermore, within the prospective cohort, patients who received non-truncated PEG-Asp demonstrated better survival than those who received a truncated dose. Then, the entire cohort was stratified into high-dose (4-5 doses, N = 45), medium-dose (2-3 doses; N = 33) and low-dose (0-1 doses; N = 46) groups, based on the number of PEG-Asp doses administrated pre-SCT. The high-dose group showed superior survival compared to the other two groups in both the entire cohort and in subgroup analysis. Our findings indicate that high-dose PEG-Asp is associated with improved outcome in adult T-ALL undergoing SCT.